The present invention relates to purity monitoring and, more specifically, to a gas or fluid purity monitor including a cryo-cooler and a quartz crystal microbalance (QCM).
Testing sensors and missile systems have components that operate with high-pressure gases and fluids. For example, heat seeking missiles use infrared (IR) sensors to detect electromagnetic radiation from targets and to allow for target detection and most IR sensors are cooled via compressed Argon, Freon, Nitrogen, Krypton or a combination thereof. These gases are sprayed on the detectors by a cryo-cooler or cryostat. While cryostats allow for very fast cool-down times and provide the sensor with enhanced target sensitivity, they are sensitive to contamination and can easily become clogged if the delivery system is not clean.
Delivery of clean gas has thus been a challenge for many years and led to the development of testing processes. The techniques used in the past for such testing have required specially trained personnel using labor-intensive processes and even then the processes tended to result in rather coarse measurements of NVR contaminant levels.